Usually, it attempts to achieve the random number generation with limited resources. The means to generate the random numbers with one's own device is indicated. (Refer to patent document 1).
Mersenne twister with Mersenne primes is a pseudo-random number generator developed by the Makoto Matsumoto and Takuji Nishimura in 1997 (Thesis was announced on January, 1998). It is proved that the period is 2^19937-1 or 623 words (19937 bits, 2492 bytes), and 623-dimensional equi-distribution property is assured. (Refer to non-patent document 1).
Besides, the introduction page of the ciphering publicly declared by the Ministry of Foreign Affairs is available. It plainly introduces the finite random number code and the infinite random number code. Here, it is described that the infinite random number code cannot be logically deciphered. (Refer to non-patent document 2).
The research is continued because the good quality random numbers for ciphering are necessary. However, demand is high for the logically complex random number generator with a fast speed, long cycle and which works on comparatively small machine. Mersenne Twister is strong from cycle point view. However, it has some weak points like it is not suitable for ciphering since the value prior to the constant random number sequence becomes predictable if constant random number sequence is output and so the demand for the new pseudo-random number generation device is high.
Patent Document 1: Japanese published unexamined application H10-247140
Non-Patent Document 1:M. Matsumoto and T. Nishimura, “MersenneTwister: A 623-dimensionally equidistributed uniform pseudorandom number generator”, ACM Trans. on Modeling And Computer Simulation Vol. 8, N0.1, January pp. 3-30 (1998) http://www.math.sci.hiroshima-u.ac.jp/˜m-mat/MT/mt.html
Non-patent document 2: Ministry of Foreign Affairs Secretariat telecommunication section, Part-time lecturer, Sadao Okumura [Diplomacy and ciphering] http://www.mofa.go.jp/mofaj/annai/shocho/e_seifu/toukou2004.html